Insect repellent composition

ABSTRACT

The present invention relates to methods of applying an insect repellent composition containing, in a physiologically acceptable medium, as active insect repellent material, at least 20% by weight of 1-methylpropyl (2-(2-hydroxyethyl)piperidine-1-carboxylate, said active insect repellent material being used in an aqueous medium with about 5% by weight of at least one copolymer of vinylpyrrolidone and hexadecene and at least one silicone oil.

This application is a continuation application of U.S. application Ser.No. 13/256,044, having a 35 U.S.C. §371(c) date of Nov. 21, 2011, whichis a national stage application of PCT/IB2010/051050, filedinternationally on Mar. 11, 2010, which claims priority to FrenchApplication No. 09 51590, filed on Mar. 13, 2009, the entire content ofeach of which is incorporated by reference herein.

The subject of the present invention is a biting insect, in particularmosquito, repellent composition.

It is known practice for people to protect themselves against insects byapplying active repellent agents to the skin. However, most of thesolutions for protecting the body against biting insects have a limitedeffectiveness time since the latter is often affected by the moisture ofthe environment. For example, the high degree of humidity in tropicalzones leads to a considerable increase in sweating in individuals, whichhas the effect of causing a premature elimination of the anti-insectcomposition applied to the surface of their skin. Similarly, the directcontact of water, for example during swimming, with such a compositionapplied at the surface of the skin, is also of course prejudicial.

This deficiency in water resistance, shown by a large number ofanti-insect compositions, therefore requires attention by the individualtreated, who must apply a new coat of composition after any prolongedcontact with water or significant sweating.

In order to overcome this deficiency, the use of film-forming agents,for instance vinylpyrrolidone copolymers, in order to increase themoisture resistance of these anti-insect compositions, has beenproposed.

The present invention, for its part, aims to propose a novel anti-insectcomposition which simultaneously has good insect repellent propertiesand a particularly increased resistance with regard to moisture.

More specifically, the present invention proposes a composition whichprovides long-lasting insect repellent protection, including underextreme climatic conditions and/or after swimming for a short period oftime.

The inventors have thus discovered, surprisingly, that the combinationof a particular film-forming agent and of a latest-generation activeinsect repellent material, such as 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1-carboxylate, makes it possible to obtainsuch a composition.

The film-forming agent under consideration according to the invention infact efficiently provides binding of the active repellent material andprevents elimination thereof in contact with water.

A first subject of the invention is therefore an insect repellentcomposition comprising, in a physiologically acceptable medium, asactive insect repellent material, at least 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1-carboxylate, said active agent beingused with at least one copolymer of vinylpyrrolidone and of a linearalkyl containing at least 16 carbon atoms.

A second subject of the invention is a method for repelling insects withrespect to a substrate, and more particularly the skin, comprising theapplication to said substrate of an effective amount of at least onecomposition as defined in the present invention.

This substrate is advantageously the skin; however, it may also be anitem of clothing or other textile material intended to protect the skinagainst insects.

As emerges from the examples which follow, the copolymer underconsideration according to the invention as film-forming agent isadvantageous in many respects.

First of all, biological tests for effectiveness under tropicalconditions have confirmed an effectiveness of 8 hours without any bite,on a composition which combines it with the active anti-insect agentretained according to the invention. These results therefore show thatthe use of this specific copolymer makes it possible to guarantee anincreased moisture resistance of the anti-insect formulation andtherefore confers on this formulation a “waterproof” nature. They alsodemonstrate that this specific film-forming agent does not, moreover,affect the reactivity of 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1-carboxylate with regard to insects. Thelatter remains effective at doses conventionally used.

What is more, the copolymer under consideration according to theinvention is found to be easy to formulate. Thus, it does not require anexcessive amount of oil for processing thereof. Consequently, it can beformulated in a non-greasy aqueous emulsion (no greasy effect, no tackyor drying-out effect, stain-free). In addition, it can be easily removedwith soapy water.

Finally, this copolymer is particularly advantageous in terms ofinnocuousness and, in this respect, is compatible with application tothe skin, even the eyelids and the lips.

Advantageously, the composition according to the invention is in theform of an oil-in-water emulsion.

More particularly, this composition is waterproof.

Active Repellent Material

The repellent composition according to the present invention contains,as active insect repellent material, at least 1-methylpropyl(2-(2hydroxyethyl)piperidine-1-carboxylate or a salt thereof.

1-Methylpropyl (2-(2-hydroxyethyl)piperidine-1-carboxylate is also knownas ICARIDIN. It is currently sold under the name SALTIDIN by the companySaltigo.

A composition according to the invention may advantageously contain from10 to 25% and preferably from 15 to 22% by weight of 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1-carboxylate, relative to its totalweight.

Of course, a composition according to the invention may also compriseanother additional active material, in particular with a repellenteffect. Said material may in particular be chosen fromN,N-diethyl-3-methylbenzamide (DEET), ethyl butylacetylaminopropionate(IR3535), citronella or else geraniol.

Film-forming Agent

The repellent composition according to the invention also contains atleast one copolymer of vinylpyrrolidone and of a linear alkyl containingat least 16 carbon atoms, as film-forming polymer. According to onepreferred embodiment variant, the linear alkyl unit is advantageously aC₁₆ to C₁₈ linear alkyl chain and preferably a C₁₆ linear alkyl chain.

More specifically, the copolymer under consideration according to theinvention is a copolymer of vinylpyrrolidone and of hexadecene or acopolymer of vinylpyrrolidone and of eicosene.

It may in particular be the following commercial products, Antaron V-216and Antaron V-220 sold by ISP (International Specialty Products).

The composition may advantageously contain from 0.1 to 15% andpreferably from 1 to 10% by weight of copolymers of vinylpyrrolidone andof a C₁₆ linear alkyl, relative to its total weight.

Other additional film-forming agents may be present jointly with thecopolymer under consideration according to the invention.

By way of nonlimiting illustration of these supplementary film-formingagents, mention may in particular be made of Tricontanyl PVP,hydrogenated diinoley/dimethyl carbonate copolymer, acrylate copolymersor else acrylate/alkyl methacrylate copolymers.

For obvious reasons, the Icaridin and the film-forming agent requiredaccording to the invention are formulated in a physiologicallyacceptable medium.

Thus, a composition according to the invention advantageously comprises,as physiologically acceptable medium, an aqueous medium and inparticular water, preferably demineralized water. This aqueous mediummay be present in an amount ranging up to 80% and preferably from 40 to80% by weight, relative to its total weight.

The composition according to the invention may also comprise one or moresilicone oils. By way of examples of silicone oils that are suitable forthe invention, mention may in particular be made of dimethicone, phenyltrimethicone, C₂₆-C₂₈ alkyl methicone, cetyl dimethicone and stearyldimethicone, and mixtures thereof.

These oils are advantageous from the formulation point of view. Theyalso give the formulations containing them a pleasant gliding nature onapplication. What is more, some of these oils also have an emollientfunction.

This silicone oil is preferably dimethicone.

Advantageously, a composition according to the invention may comprisefrom 0.1 to 10% and preferably from 1 to 5% by weight of siliconeoil(s), relative to its total weight.

The composition is advantageously in the form of an emulsion, inparticular an oil-in-water emulsion.

With regard to its emulsion-type formulation, a composition according tothe invention generally advantageously comprises one or moreemulsifiers. This emulsifier may be chosen from sucrose esters, glycerolfatty esters, fatty acids, and ethoxylated fatty alcohols, and mixturesthereof.

The composition according to the invention may also advantageouslycomprise one or more humectants. This humectant may be chosen fromglycols, such as glycerol, propylene glycol or else dipropylene glycol,and waxes, such as shea butter or beeswax, and mixtures thereof.

The humectant is preferably glycerol.

Likewise, a composition according to the invention may also comprise oneor more emollients. By way of examples of emollients, mention may mostparticularly be made of C₁₂ to C₁₅ alkyl benzoate, isopropyl palmitate,isopropyl myristate, ethylhexyl palmitate, plant oils, mineral oils andsilicones, and mixtures thereof.

The emollient is preferably C₁₂ to C₁₅ alkyl benzoate.

The composition according to the invention may also comprise one or moregelling agents chosen from sucrose palmitate, glyceryl stearate andglyceryl stearate citrate, and mixtures thereof.

According to one embodiment variant, a composition according to theinvention may also comprise an active anti-UV agent capable ofconferring on said composition protective properties with regard to UVexposure.

The composition according to the invention may also comprise theconventional additives in the field, for instance those chosen from thenonexhaustive list such as chelating agents, preservatives, pHregulators and fragrances.

As specified above, the composition is advantageously in the form of anemulsion, in particular an oil-in-water emulsion. This composition maybe in the form of a cream, a milk or a gel, which can be applied asappropriate by spraying.

The present invention is also directed toward the use of an insectrepellent composition according to the invention. More specifically, itis directed toward a method for repelling insects from skin, comprisingthe application of a sufficient amount of a composition as definedaccording to the present invention to a substrate, such as the skin, ora substrate intended to be brought into contact with said skin.

The examples and figures which follow hereinafter are given by way ofnonlimiting illustration of the invention.

EXAMPLE 1

Topical Formulation According to the Invention

% BY TRADE NAME INCI NAME FUNCTION WEIGHT Saltidin (Icaridin)Hydroxyethyl Active 20 sold by Saltigo isobutyl mosquito piperidinerepellent carboxylate agent Antaron V 216 sold VP/HexadeceneFilm-forming 5 by ISP (International copolymer agent Specialty Products)DC 200 Fluid 100 Dimethicone Silicone 2 CST Tegosoft TN C₁₂-₁₅ AlkylEmollient 2 Benzoate Demineralized water Aqua Solvent Qs GlycerolGlycerin Emollient 5 Arlatone V 175 Sucrose Palmitate, Emulsifier 1.10Glyceryl Stearate, Glyceryl Stearate Citrate, Sucrose Mannan, XanthanGum Carbopol EDT 2050 Carbomer Gelling agent 0.10 Disodium EDTA DisodiumEDTA Chelating agent 0.10 Euxyl PE9010 Phenoxyethanol, Preservative 0.80Ethylhexylglycerin Triethanolamine Triethanolamine pH regulator 0.10Yakusa fragrance Fragrance Fragrance 1.50

EXAMPLE 2

The effectiveness of the formulation of example 1 was assessed withrespect to Anopheles stephensi mosquitoes.

In the absence of a French standard, the method follows the followingguidelines:

WHO General Recommendations: WHO/CDS/WHOPES/2001.2

ASTM (American Society for Testing and Materials): ASTM E951-94(laboratory)

The tests are carried out with females of mosquitoes raised in thelaboratory: Anopheles stephensi (strain ORSTOM).

The females used for the tests are 6 to 10 days old and were not fedduring the preceding 24 hours (no blood meal) in order to increase theiraggressiveness.

The blood meal target is a hairless mouse kept in a containment cage(eyes protected) and which is coated with a test product (0.1 g/60 cm²).Application is by pipette.

30 minutes after application of the product, the mouse is then placed ina cage containing approximately 200 females (prior elimination of themales by food gradient).

The test lasts 5 minutes and, during this period, the number ofmosquitoes which have landed on the mouse (“landing effect”), and thenthe number of actual bites (unless there is a clear ineffectiveness),are recorded.

The test is stopped once there have been 5 actual bites.

The test is recommenced with new batches of mosquitoes, after 2, 4, 6,7, 8 and 9 hours following application according to the limit ofpersistence of the product (the mouse is released between times).

The same test is carried out with mice having received no treatment, inorder to verify the natural tendency of the mosquitoes to bite. It isverified that there are at least 10 landings and more than 5 bites in 30seconds in order to validate the test.

The test is stopped after 5 bites (“stop”) in the table of datarepresented below.

The “landing” data correspond to the number of mosquitoes landing on thezone treated, but which leave again without having bitten. This datumcan provide information on the limit of persistence of the products,since the mosquitoes increasingly approach the treated zone until therepellent effect is insufficient and there is actual biting.

During and between these sessions, the mice are kept in a “tropical”atmosphere under controlled conditions at 27±1° C. and 70±5% relativehumidity.

The cages are changed at each unit test and place three meters apart.

Three repeats are carried out per test formulation and on threedifferent mice, i.e. nine unit tests per formulation.

The results are given in table I hereinafter.

TABLE I i. ANOPHELES T0 + 2H T0 + 4H T0 + 6H T0 + 7H T0 + 8H T0 + 9HSTEPHENSI mouse rep. B L B L B L B L B L B L Formulation 1 1 0 0 0 0 0 00 0 0 3 stop stop Example 1 2 0 0 0 0 0 0 0 0 0 1 stop stop 3 0 0 0 0 00 0 1 0 0 stop stop 2 1 0 0 0 0 0 0 0 0 0 2 stop stop 2 0 0 0 0 0 0 0 00 3 stop stop 3 0 0 0 0 0 0 0 0 0 2 stop stop 3 1 0 0 0 0 0 0 0 0 0 4stop stop 2 0 0 0 0 0 0 0 1 0 3 stop stop 3 0 0 0 0 0 0 0 0 0 2 stopstop Test without 1 1 stop stop stop stop stop stop stop stop stop stopstop stop product 2 stop stop stop stop stop stop stop stop stop stopstop stop 3 stop stop stop stop stop stop stop stop stop stop stop stop2 1 stop stop stop stop stop stop stop stop stop stop stop stop 2 stopstop stop stop stop stop stop stop stop stop stop stop 3 stop stop stopstop stop stop stop stop stop stop stop stop 3 1 stop stop stop stopstop stop stop stop stop stop stop stop 2 stop stop stop stop stop stopstop stop stop stop stop stop 3 stop stop stop stop stop stop stop stopstop stop stop stop B: number of bites rep: repeat L: “landing” = numberof mosquitoes landing without biting on the treated zone stop = the testis stopped when more than 5 bites are observed

It may be noted that, under the conditions of these tests, with thesamples provided, insect strains and method under consideration, theformulation showed a highly significant repellent effect with respect toAnopheles stephensi. The persistence of action is 8 hours.

The invention claimed is:
 1. A method for repelling insects from pets,comprising: applying a sufficient amount of an insect repellentcomposition to the pet, the insect repellent composition comprising, ina physiologically acceptable medium, as active insect repellentmaterial, at least 20% by weight of 1-methylpropyl (2-(2-hydroxyethyl)piperidine-1-carboxylate, said active insect repellent material beingused in an aqueous medium with about 5% by weight of at least onecopolymer of vinylpyrrolidone and hexadecene and at least one siliconeoil.
 2. The method according to claim 1, wherein the insect repellentcomposition comprises from 40 to 80% by weight of the aqueous medium,relative to its total weight.
 3. The method according to claim 1,wherein the insect repellent composition comprises one or more siliconeoils chosen from dimethicone, phenyl trimethicone, C₂₆-C₂₈ alkylmethicone, cetyl dimethicone and stearyl dimethicone, and mixturesthereof.
 4. The method according to claim 1, wherein the insectrepellent composition comprises from 0.1 to 10% by weight of siliconeoil(s), relative to its total weight.
 5. The method according to claim1, wherein the insect repellent composition comprises one or morehumectants chosen from glycols, waxes and mixtures thereof.
 6. Themethod according to claim 1, wherein the insect repellent compositionfurther comprises one or more emollients chosen from the esters C₁₂ toC₁₅ alkyl benzoate, isopropyl palmitate, isopropyl myristate, ethylhexylpalmitate, plant oils, mineral oils and silicones, and mixtures thereof.7. The method according to claim 1, wherein the repellent composition isin the form of an emulsion.
 8. The method according to claim 1, whereinthe insect repellent composition further comprises one or moreemulsifiers chosen from sucrose esters, glycerol fatty esters, fattyacids and ethoxylated fatty alcohols, and mixtures thereof, and/or oneor more gelling agents chosen from sucrose palmitate, glyceryl stearateand glyceryl stearate citrate, and mixtures thereof.
 9. The methodaccording to claim 1, wherein the insect repellent composition iswaterproof.
 10. The method according to claim 1, wherein the insectrepellent composition is in the form of one of a cream, a milk or a gel.11. The method according to claim 1, wherein the insect repellentcomposition comprises from 1 to 5% by weight of silicone oil(s),relative to its total weight.
 12. The method according to claim 1,wherein the insect repellent composition comprises one or more ofglycerol, propylene glycol, dipropylene glycol, shea butter, andbeeswax, and mixtures thereof.
 13. A method for increasing resistancewith regard to moisture/water of a composition comprising as activeinsect repellent material at least the 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1-carboxylate, said method comprising thestep of formulating this composition in an aqueous emulsion comprising,in a physiologically acceptable medium: at least 5% by weight of atleast one copolymer of vinylpyrrolidone and hexadecane; and at least onesilicone oil.
 14. The method according to claim 13, wherein thecomposition comprises at least 20% by weight of 1-methylpropyl(2-(2-hydroxyethyl)piperidine-1 -carboxylate, relative to the totalweight of the formulated composition.
 15. A method for repelling insectsfrom a textile material, comprising the step of applying a sufficientamount of an insect repellent composition to the textile material, theinsect repellent composition comprising, in a physiologically acceptablemedium, as active insect repellent material, at least 20% by weight of1-methylpropyl (2-(2-hydroxyethyl) piperidine-1-carboxylate, said activeinsect repellent material being used in an aqueous medium with about 5%by weight of at least one copolymer of vinylpyrrolidone and hexadeceneand at least one silicone oil.